Method and apparatus for wetting sheets of photographic foil material



.Sept. 24, 1963 Filed Feb. 25, 1962 G. SCHWIENBACHER METHOD AND APPARATUS FOR WETTING SHEETS 0F PHOTOGRAPHIC FOIL MATERIAL 2 Sheets-Sheet 1 P 24, 1963 G SCHWIENBACHER 3,104,603

METHOD AND APPARATUS FOR WETTING SHEETS 0F PHOTOGRAPHIC FOIL MATERIAL Filed Feb. 25, 1962 Y 2 Sheets-Sheet 2 3,104,603 Pl: APPARATUS FOR WETTING SHEETS F PHOTOGRAPHHC FUEL MATE Georg Schwienbacher, Zurich, Switzerland, assign'or to Photo-Entwicklungsgerate AG, Zurich, Switzerland Filed Feb. 23, 1962, Ser. No. 175,191 Claims priority, application Switzerland Feb. 23, 1961 THGD r photostats, for instance by successively using a developer and a stabilizer, the sheet to be treated, such as photographic paper or a film, is passed over a wetting roller a portion of which is immersed in the treating solution. The treating solution is received in a vessel which, at any rate, should contain a sufficient amount of solution to allow treatment of a relatively large number of single sheets. In this known procedure, it must be noted that the treating solution can never be completely utilized owing to the fact that the solution is subject to rapid oxidation and will soon .become unsuitable for use. When only a few photostat copies are produced from time .to time, ie where the photo-copying device is used only occasionally, the premature spoiling of the developing solution will result not only in a considerable loss of material, but also in a loss of working time, as such receptacles must in practice be daily emptied, cleaned and refilled before use.

The objectof the present invention is to avoid this troublesome and time-consuming mode of operation and to eliminate the uneconomical waste of material. The

vmethod according to the invention comprises the step of feeding to the surface of the wetting roller a predetermined quantity of treating solution sufiicient for wetting a limited number of sheets only.

According to a further feature of the present invention, an apparatus for wetting sheets-of photographic foil material comprises a wetting roller, means for passing a sheet of foil material over the wetting roller, a closing device including a container for treating solution, and means for feeding a predetermined quantity of treating solution to the wetting roller, an open space being provided adjacent the wetting roller for receiving the predetermined quantity of treating liquid and transferring it to the roller surface.

The invention will now be fully described by referring to the accompanying drawings, in which several modifications of the apparatus are diagrammatically shown.

FIG. 1 shows in longitudinal section an apparatus according to the invention as used for the production of photostats with a wetting rollereach for the developer and the stabilizer.

FIGS. 2 and 3 illustrate modifications of the apparatus of FIG. 1, however, only the essential components being shown.

FIG. 4 illustrates details of a further modification.

FIG. 5 is a fragmentary perspective view of the modification of FIG, 4.

Referring to FIG. 1 the apparatus comprises a lower housing portion 1 in which a collecting trough land a receptacle 3 for the spent treating solution is enclosed. The trough 2 communicates through a discharge opening 4 with receptacle 3. For the sake of simplicity, the upper portion of the'housing is 'not shown in the drawmg. 4

Photographic paper 5 to be treated is engaged and moved between a pair of rollers '6 including upper and lower rollers 6' and 6" which are rotated by a motor,

areas-3 Patented Sept. 24, 1%63 not shown, in the direction of the arrows to advance the sheets at the desired speed. Sheet 5 is carried by the pair of rollers 6 to a first wetting roller 7 which is rotated in the same direction as roller 6" and in such a manner that the peripheral speed 'of the roller will be higher than the travelling speed of the sheet to be treated. In applying thus the treating solution to the coated surface of the sheet 5 facing roller 7 an excellent wetting of this surface will be achieved.

in the upper housing portion (not shown) provision is made of a dosing device 8 for treating liquid, consisting of a storage container 9 which is hermetically sealed by means of a cover 10 made of resiliently yielding material, and which has a discharge tube 11 ending above the wetting roller 7. A profiled bar 12 of angular crosssection is arranged parallel with the axis of roller 7, so that one of its legs 12' extends horizontally below the roller and is slightly spaced from the latter, whereas the other leg 12" extends vertically after the roller as seen in the direction of sheet feeding indicated by V. The distance of the leg 12 from the roller surface is in the order of about 1 mm. (0.04 inch) and the same spacing is selected for the distance between the top edge of leg 12" and the sheet 5 to be treated. The purpose of this arrangement will be described later.

As seen in the direction of feed V, the first wetting roller 7 is followed by another wetting roller 13 which is rotated in the same direction and which has the same peripheral speed as roller 7. Corresponding to leg 12' below roller 7 a simple flat bar 14 is disposed below the second wetting roller 13, the distance between the bar 7 and the surface of the roller being also in the order of 1 mm. Here again, the roller '17 is associated with a dosing device 15 the structure of which is similar to dosing device 8, comprising a container 9 and a cover 10. The discharge pipe 11 also opens above roller 13. Between the rollers 7 and 13 the sheet is slightly bent downwards by a holding down lever 16.

In the direct-ion of feed V, the roller 13 is followed by a further pair of rollers 17 consisting of a lower roller i7 and an upper roller 17" the latter having a somewhat larger diameter than the lower roller. As compared with the surface of roller 17', roller 17 is lined with a softer material so that roller 17 produces a depression on the circumferential surface of roller 17". The purpose of such an arrangement will also be fully described hereafter. The pair of rollers 17 which is motor driven with a speed corresponding to the travelling speed V, and is preceded by a stripping edge 18 which makes contact with the coated lower surface ofthe sheet 5 to be treated.

The container 9 of the dosing device 8 contains developer liquid, while the container 9 of the dosing device 15 contains stabilizer liquid.

Prior to introducing the sheet to be treated into the apparatus, a drop of treating solution from each of the dosing devices 8 and 15, respectively, is caused to discharge on the surfaces of each roller 7 and 13 by exerting pressure wi-tlra finger upon cover 10 of the dosing de vices, which cover may be made of rubber, for instance.

This liquid drop is carried down into the gap 19 confined between the roller 7 and the leg 12", and between the roller 13 and the flat bar 14, respectively, where the liquid is immediately distributed over the length of the gap along the roller, so as to fill the whole gap. In this manner the entiresurface of the rollers 7 and 13 will be wetted and kept pe'rfectly'wet.

The sheet 5 can now be introduced between therollers 6' and'6"from' where it is automatically carried on by the movement'of the rollers. The coated surface of the sheet facing rollers 7 and 13 will be perfectly wetted by the liquid taken up by the rollers in the gap 19 during r 3 r V their rotation. The liquid in the \gap 19 will be gradually used up, since the amount of liquid discharged by exertion of pressure on the coverslti' prior to introducing the sheet will scarcely suffice for the treatment of more than one sheet. To make sure that the sheet to he treated is thoroughly wetted, it may be advisable to choose an amount of liquid slightly in excess of the quantity required for one sheet. In doing so a remainder of liquid sary for the treatment of a 7 used up in continuous operation before aging; in intermittent operation, however, and especially when the movement of the'rollers is stopped, the liquid is also allowed to discharge into the collecting trough and into the receptacle 3, so that it cannot becomernixed up with the fresh solution supplied to the Wetting roller when a further sheet is going to be treated.

will be weft in the gap which may be sufficient for treati the collecting trough 2 and subsequently gather in the.

receptacle 3. This makes clear that every sheet is .wetted with a fresh treating solution and that, in practice, only the quantity of treating solution actually required for the Wetting of the sheets to be treated will be used up. Further, it is understood that the quality of the sheets thus treated will be considerably improved, since they are prevented from coming into contact with a spoilt solution, and since the fresh supply of solution is prevented from becoming mixed with remainders. of spoilt solution.

Leg'12" of the angle bar 12 is necessary to avoid that the end of sheet 5 is carried downward by the rotating roller 7 whose peripheral speed is higher than the advance speed of the sheet, as otherwise the-back side of the sheet would also be wetted. The free edge of member 13 serves to wipe off any excess liquid from the coated side of sheet 5 and to preventthus any excess liquid from being carried over the roller 17. If desired, the stripping edge 18 -may be omitted. By makinga roller 17 of softer material, in whichgthe roller 17' is caused to form a depression, the circumferential surface of the roller 17" is prevented from taking up liquid from roller 17- after the sheet 5 has passed and from wetting the backside of the next sheet.

The above description makes clear that each of the wetting rollers is associated. with an open space 19 essentially'designed for receiving a dosed amount oftreating:

liquid. In theembodi-ment shown in FIG. 1 this space is formedby the surface of roller 7 and leg .12, or by the surface of roller 13 and flatbar 14' andconstitutes a gap in which the treating liquid is retained by'capill-ary action. As set forth above, the dosed amount of liquid" is in principle determined by the quantity of treating I solution required for the treatment of one sheet, but it must be understood that for continuous operation twice or three times as much, or even more treating solution can readily be supplied to the gaps 19, since there is no risk of spoiling when the sheets are treated immediately oneafter another. When exerting a stronger pressure of fingers upon the cover of the dosing device, ,or pressing repeatedly on the covers will cause an increased supply of treating liquid to the corresponding gaps.

The embodiment shown in FIG. 2 differs from'that shown in *FIG.-1 in so far as the roller 7 .is' preceded by a counterroller ZOengaging the roller 7 and turning at the same peripheral speed, but in opposite direction as indicated by 'the'arrows. The gap 21 between the two rollers 20 and 7 which'is downwardly closed because of the mutual engagement of the two rollers, but which could also be downwardly open by modifying the distance between the two rollers, forms a receptacle which is laterally open at both roller ends in order to receive the dosedjamount of treating solution supplied from the :roller 31 for the developer; a sheet 32 to be treated is fed to the wetting roller by means'of a pair of rollers 33 whose rollers 33' and-33" are rotated by a motor at a desired speed and in the direction of rotation as indicated by the arrows. As canbe seen from the drawing, the wetting roller 31 is rotated in the same direction as roller 33 and the arrangement is such as to make the peripheral speed of the wettting roller higher than the travelling speed of the sheet to be treated. In applying thus the treating solution to the coated side of the sheet facing the roller, a perfect wetting will be obtained.

A strip 34 of resilient material, preferably of plastics, is inserted in a ledge 35 disposed below the wetting roller 3 and extending longitudinally thereof; thearrangement is such that the strip 34 rests against the roller 31, notably against the side of roller remote from the pair of rollers 33, whereby the strip is sharply'deilected immediately above the ledge 35. It will be noted, as seen in FIG. 5, that the ledge is slightly bent away from the roller at 36 so that the strip 34 is less sharply deflected at point 36 than adjacent to it. Thus a line of contact '37 is formed between the strip 34 and roller 31 which slopes down towards both ends of the roller. Prior to introducinga sheet to be treated into the apparatus, a drop of treating solution, for example developer, is discharged from the dosing device 8 iontothe wetting roller 31, and

into the open receptacle 38 formed by roller 31 and the strip 34 and roller 31 on both sides of the point 37, over the whole length of the roller whose circumferential surface will thus be perfectly wetted. As sheet 32 is introduced and carried through the apparatus, its coated side will be wetted by roller 31, and the liquid discharged into the space 38 will be gradually used up. A remainder possibly left in the space 38 after treatment of a sheet is allowed to drain at both ends of the roller, in case the apparatus is not used for sometime. Thus, every sheet will be wetted wuss fresh supply oftreatin-g liquid. Nevertheless the apparatus will be immediately ready for operation as a result ofthequick distribution of the treating solution over the whole length of thewetting roller. c a

I It is understood that the same means asspecified above can also be used for the applicationof the stabilizing 'Iclaimf a I 1. An apparatus for wetting sheets of photographic foil. material'with treating solution, comprising a wetting roller,means for passing a sheet of foil material over the wetting roller, a' d-osing device, including a container for treatingsolution, means for feeding a predetennined dosing device 8. The counterroller 20 oflfers the advantage to act also as a wetting roller. This embodiment V ledge along a bentline so thatsaid strip engages the also satisfies the requirement that only as much treating solution be supplied to the wetting rolleruas will be n'eces quantityof treating solution fromthe'container tothe wetting-roller, a ledge extending longitudinally of and below the wetting roller, and a strip of flexible material inserted insaid :ledge extending. longitudinally of the wetting roller alonga bent'line sloping down from a few sheets and as will be point intermediate the ends of the roller towards both ends thereof providing an open space between the circumferential surface of the roller and the strip for recei-ving the predetermined quantity of treating solution and transferring the same to the roller surface.

2. A method for Wetting sheets of photographic foil 'material with a treating solution comprising the steps of so that the solution in the gap will be transferred by the roller to the sheet and repeating the above steps.

References Cited in the file of this patent UNITED STATES PATENTS 826,897 Shely July 24, 1906 11,811,689 Hands June 23, 1931 1,916,108 Hall June 27, 1933 2,676,563 Montgomery et a1. Apr. 27, 1954 2,981,171 Hruly et a l. Apr. 25, 1961 3,010,845 Schornstheimer Nov. 28, 1961 

1. AN APPARATUS FOR WETTING SHEETS OF PHOTOGRAPHIC FOIL MATERIAL WITH TREATING SOLUTION, COMPRISING A WETTING ROLLER, MEANS FOR PASSING A SHEET OF FOIL MATERIAL OVER THE WETTING ROLLER, A DOSING DEVICE INCLUDING A CONTAINER FOR TREATING SOLUTION, MEANS FOR FEEDING A PREDETERMINED QUANTITY OF TREATING SOLUTION FROM THE CONTAINER TO THE WETTING ROLLER, A LEDGE EXTENDING LONGITUDINALLY OF AND BELOW THE WETTING ROLLER, AND A STRIP OF FLEXIBLE MATERIAL INSERTED IN SAID LEDGE EXTENDING LONGITUDINALLY OF THE LEDGE ALONG A BENT LINE SO THAT SAID STRIP ENGAGES THE WETTING ROLLER ALONG A BENT LINE SLOPING DOWN FROM A POINT INTERMEDIATE THE ENDS OF THE ROLLER TOWARDS BOTH ENDS THEREOF PROVIDING AN OPEN SPACE BETWEEN THE CIRCUMFERENTIAL SURFACE OF THE ROLLER AND THE STRIP FOR RECEIVING THE PREDETERMINED QUANTITY OF TREATING SOLUTION AND TRANSFERRING THE SAME TO THE ROLLER SURFACE. 